Electric shaver



Aug. 19, 1941.- .1. OSTER 2,253,195

ELECTRIC SHAVER i Filed March :51, 1939 I 2 Sheets-Sheet 1 Patented Aug 19,1941

' ELECTRIC SHAVER John Oster, Racine, Wis., assignor to John Oster Manufacturing Company, Racine, Wis., a corporation of Wisconsin Application March 31, 1939, Serial No. 265,245

6 Claims.

This invention relates to so-called electric shavers, and refers particularly to the shaving head thereof. v

Nearly all of the many electric shavers now on the market are subject to the objection that they will not shave close, and that they are slow and require successive passes over the same area to obtain maximum effectiveness.

The present invention, therefore, has as one of its objects to provide an improved cutter head for power driven shavers, which makes possible closer shaving through .a new method of cutting.

Another object. of this invention is to provide a cutter head for electric shavers which is so effective that one stroke across a given area is sufficient to completely shave all hair therefrom. Another object of this invention is to provide an electric shaver of the character described with novel means for detach'ably holding the cut-' ter head properly positioned on the shaver and for maintaining the cutters under the correct amount of tension.

Another object of this invention is to provide a cutter head of the character described which is simple in design, and which is readily detachable from the body or supporting structure of the shaver.

With the above and other objects in view which will appear as the description proceeds, this invention resides in the novel construction, combimanner'in which the cutting action is effected; and

Figure 6is an end view of the cutter head showing a modified embodiment thereof.

Referring now particularlyto the accompanying drawings in which like numerals indicate like parts, the numeral 5. designates the housing or body of an electric shaver in which an electric motor (not shown) is housed. The drive shaft 6 of the motor projects into an oblong cavity or recess 1 in the front end of the body where it mounts an'eccentric driving bushing 8. The eccentric driving bushing reciprocates the movable blade 9 of a cutter head l0 detachably mounted in the recess 1. i

The cutter head, in addition to the blade 9. incorporates two stationary blades ll between which the movable blade reciprocates. All of the blades have their outer edge portions provided with teeth, the teeth l2 on the movable blade being spaced farther apart than the teeth IS on the stationary blades.

Any suitable manner of guiding the movable blade and maintaining it properly positioned with respect to the stationary blades may be employed, and in the present instance, the movable blade has two longitudinal ribs I4 on'its 0ppositefaces which ride in correspondingly shaped and positionedlongitudinal grooves .l5 in the inner faces of the stationary blades.

The meeting toothed outer edge portions of the stationary and movable blades are ground to fit accurately and effect a cutting action as the teeth on the movable blade pass the teeth of the stationary blades.

The three blades are held in proper assembled relation and in place in the cavity or recess 1 by a spring clip I 6 securedin the bottom of the cavity or recess. The wings of this clip have ridges I! on their outer extremities to snap into grooves IS in the outer faces of the stationary Figure 1 is a side view of a shaver constructed in accordance with this invention, parts thereof being broken away and in section;

Figure 2 is a top plan viewof the shaver with a portion of its housing broken away and in section;

Figure 3 is a perspective view showing the front end of the housing and the component 7 parts of the cutter head, disassembled;

Figure 4 is a sectional view through Figure 1 on the plane of the line 4-4;

Figures 5 is an enlarged cross sectional view through the cutter head per se to illustrate the blades when the assembled cutter head is properly positioned in the recess, at which time the inner edges of the stationary blades preferably engage the bottom wall of the clip, and the ends of the stationary blades contact end walls It struck up from the bottom wall of the clip.

The clip is secured in the cavity or recess l by screws or other suitable fastenings passing through holes 2|] in the bottom wall of the clip and threaded into the adjacent portion of the body. A large hole in the bottom wall of the clip accommodates the eccentric driving bushing.

Reciprocal motion is imparted to the movable blade by having the eccentric bushing engage in a recess 2! formed in the inner edge of the movable blade.

While the movable blade has suf-.

ing an inward clamping force on the guards so as to provide the tension necessary for proper cutflcient thickness to insure the edges of the recess 2| maintaining proper engagement with the eccentric bushing throughout its entire throw, it need not be so thick that the bushing lies between the planes of its opposite faces at all positions, as 'the adjacent portions of the stationary blades can be cut away as shown.

In using the shaver, it is held in a position substantially perpendicular to the surface of the skin,

as shown in Figure 4, and as a consequence, the.

area of the skin lying between the edges of the stationary blades is stretched and bulged outwardly. This action is permitted by virtue of the fact that the outer edge of the movable blade is spaced inwardly from the edges of the stationary blades and is preferably formed on an are, as shown in exaggerated form in Figure 5.

Hence, the hair is caused to assume positions extending across the line of parting between the movable and stationary cutter blades as the shaver is moved across the surface of the skin, and as a result, the hair is ,cut off close to the surface of the skin during one sweep of the shaver.

As stated, the spaces between the teeth of the movable blade are wider than those of the stationary blades which act as combs. This affords more time-for the hair to move into the spaces between the teeth of the movable=blade, as willment, any hair held down by the teeth of one blade will be aligned-with the spaces of the other blade to enter the same upon the return stroke of the shaver. e

To remove the cutter head, it is only necessary to grip the same at the ends of its stationary clip It being of {such strength as to yield and release the cutter head in .response to such a pull, although under all ordinary circumstances, the tension of the clip is sufficient to hold the head in place. I

From the foregoing description taken in connection with the accompanying drawings, it will be readily apparent that this invention provides a substantial improvement in so-called electric shavers through the use of a spring clip for the cutter head which in addition to detachably maintaining the cutting head assembled and under spring tension, alsoholds the stationary guards or comb members against movement during reciprocation of the movable cutter.

What I claim as my invention is: 1. In a shaver of the character described: a movable cutting blade having a toothed edge portion; toothed guards overlying the opposite side faces of the movable cutting. blade, said toothed guards having shoulders on their outer faces between and parallel to their outer toothed edges and their inner edges; and a spring member disposed over the inner edges of the toothed guards and having a substantially U-shaped.

cross section to provide resilient side walls engageable with the shoulders on the toothed guards to detachably maintain the guards and the movblades'and apply a smart outward pull,'the spring ting action at opposite sides of the movable cutting blade.

2. In a shaver of the character described: a movable cutting blade having a toothed edge portion; toothed guards overlying the opposite side faces of the movable cutting blade and cooperating therewith to provide a cutting head having cutting edges at opposite sides of the movable cutting blade; a spring clip having a substantially U-shaped cross section so as to provide spaced resilient side walls for embracing the inner end of the cutting head to thereby maintain the cutting edges thereof under spring tension; and interengaging means on said side walls and the adjacent faces of the toothed guards maintained operative by the resiliency of said side walls for releasably holding the cutting head assembled with respect to'th spring clip.

3. In a shaver of the character described: a movable cutting blade having a toothed edge portion; toothed guards overlying the opposite maintain the cutting edges thereof under spring tension; interengaging means on said side walls and the adjacent faces of the toothed guards maintained operative by the resiliency of said side walls for releasably holding the cutting head assembled with respect to the spring clip; and end abutments on the spring clip cooperating with the resilient side walls thereof to hold the toothed guards stationary during movement of the movable cutting blade.

4. In a shaver of the character described: a cutting head comprising a pair of spaced apart comb members having shoulders on their outer faces between and parallel to their outer toothed edges and their inner edges, and a movable cutter member reciprocable between said comb members and having teeth on its outer edge cooperating with the teeth of the comb members to provide cutting edges at opposite sides of the movable cutter member; means for detachably securing the cutting head members assembled and in cutting relationship comprising, a part having a bottom wall engaged with and overlying the inner edges of the comb members; and spaced apart resilient side walls extending up from the bottom wall of said part to resiliently clamp the cutting head therebetween,.said resilient side walls being arranged to engage and exert an inward and downward force on the shoulders of the comb members so as to maintain the cutting head engaged with the bottom wall of said part and the movable cutter member clamped under tension between the comb members.

5:. In a shaver of the character described: a cutting head comprising a pair of spaced apart comb members having shoulders on their outer faces between and parallel to their outer toothed edges and their inner edges, and a movable cutter member reciprocable between said comb members and having teeth on its outer edge cooperating with the teeth of the comb members to provide cutting edges at opposite sides of the movable cutter member; means for detachably securing the cutting head members assembled and in cutting relationship comprising, a part having a bottom wall engaged with and overlying the inner edges of the comb members; spaced apart resilient side walls extending up, from the bottom wall of said part to resilientlyv clamp the cutting head therebetween, said resilient side walls being arranged to .engage and exert an inward and downward force on the shoulders of the comb members so as to maintain the cutting head engaged with the bottom wall of said part and the movable cutter'member clamped under tension between the-comb members; and end abutments on said part engaging the oppositeends'of the comb members and cooperating with the resilient side walls to' hold the comb members-stationary with respect to the movable cutter member during reciprocation thereof.

6: In a shaver oi the character described: a movable cutter; comb members disposed flatwise against opposite sides 'of the movable cutter;

- motion between the comb'membrs; and a single teeth on the movable cutter cooperating with the teeth of the comb members to provide a cutting area at opposite sides of the movable cutter; a readily separable connection between the comb members and the movable cutter operable to guide the movable cutter for reciprocal spring clip'havlng resilient sidewalls arranged to contact the outside facesof the comb members at points adjacent to said connection so as to maintain said connection between the movable cutter and the comb mnembers operative "whereby the movable cutter'andthe comb members are maintained in cuttingrelationship with the necessary tension at the cutting areas; and

a detent connection between said resilient side walls and the outerfaces of the comb mem bers for detachably maintaining the comb members and movable cutter assembled as a unit with the clin. a

JOHN OSTER. 

